Forge 1.20.1
Guard Villagers 1.6.11
Oh The Biomes We've Gone 1.6.5

Guards do not appear in most villages from this mod, but they do appear in the pumpkin patch village, where they should not appear (because it is not inhabited by villagers, but by pumpkin wardens)

What's really going on here is that the pumpkin patch village is the only village that actually spawns the golem, while the other villages do not spawn a golem upon generation at all. Guards spawn in a village only if a golem is present. I will see what I can do about this so for now I will leave this open.

With the new system that's going to be added in 1.21.1 (and hopefully for 1.20.1 too) this problem is fixable by adding the structure files for the other villages into a config option. However pumpkin patches will still spawn guards unless you find a way to make it so that the pumpkin patch village does not use the iron_golem.nbt file and instead uses a unique file (this should be doable via datapacks.)

does not use the iron_golem.nbt file and instead uses a unique file

@seymourimadeit Could you explain in more detail what I should do for this? What is this unique file and how should I use it through the datapack?

does not use the iron_golem.nbt file and instead uses a unique file

@seymourimadeit Could you explain in more detail what I should do for this? What is this unique file and how should I use it through the datapack?

If you do not want guards spawning in pumpkin patch villages then you are going to need to either ask the people who made Oh The Biomes We've Gone to create a unique iron_golem.nbt file for the village structure to use to prevent other mod's from interfering or look through the OTBWG's datapack and modify the files for the pumpkin patch village to use a unique pool that's not the vanilla minecraft's version of iron_golem.nbt so iron golems can spawn in pumpkin patch villages but guards do not.